1. Field of the Invention
This invention relates, in general, to composite lined closures and more particularly to closures having a seal liner and methods for their use.
2. Description of Related Art
An exemplar of known caps, which are used with large water containers of the type used with water dispensers and water-coolers is disclosed by U.S. Pat. No. 5,232,125 to Adams. The cap disclosed by the Adams '125 patent includes a tension ring configured to fit under the neck bead, that is the crown of a container neck. The cap disclosed by the Adams '125 patent also includes internal upper and lower seal beads on the inside of the wall of the corner which are configured to engage the container lip and seal against leakage.
The large water containers used with such known caps are generally blow molded and include neck finishes that are trimmed or otherwise finished using conventional methods. Although the neck finishes are somewhat standardized within the container industry, the actual heights of container neck crowns tend to vary to some degree due to the trimming and other finishing processes. In the event that excessive material is removed from a container neck crown during trimming, the upper and lower seal beads of known caps of the type disclosed by the Adams '125 patent might not effectively seal against the crown.
Some known caps for large water containers include a liner to increase the integrity of the seal. One common form of liner comprises a compressible foam liner. Because they are highly compressible, these foam liners are able to accommodate a wide range of bottle dimensions and common bottle finish defects. These plastic foam liners are most often cut as a disk or an annular “donut” from a sheet of material and then inserted or punched into the closure or bottle cap. An exemplar of a cap that has a foam liner is disclosed by U.S. Pat. No. 5,687,865 to Adams et al.
Disadvantageously, the use of a foam liner requires additional assembly steps. For example, the liner is generally inserted into the cap after the cap is formed and prior to the application of the cap to a large water container, thus leading to increased production costs. Also, the only retention mechanism holding the foam liner within the cap is generally an interference fit between the liner and the tension ring of the cap. In this case, a certain amount of liner shifting with respect to the cap can occur for various reasons. For example, the liner might not be inserted perfectly axially with respect to the cap during mechanical cutting and insertion processes. Also, the liner may shift during application of the cap to a container neck.
As the only retention mechanism holding a foam liner in the cap is generally the above-mentioned interference fit, the foam liner may dislodge and fall out from the cap prior to application to a container. In the event that the liner falls out and the cap is applied to the container without the liner, the resulting liquid seal between the cap and the container neck may be severely diminished if not completely compromised.
What is needed is a closure that overcomes the above and other disadvantages of known caps.